The role of interferon in the therapy of epidemic Kaposi's sarcoma

Kaposi's sarcoma (KS) is the major neoplastic complication of the acquired immune deficiency syndrome (AIDS). Although most patients succumb to infectious complications of AIDS rather than as a direct consequence of the tumor, KS may, in some cases, pursue an aggressive clinical course resulting in considerable morbidity. A subset of KS patients, characterized by lack of systemic "B" symptoms (fever, weight loss, night sweats), absence of prior opportunistic infection, and relative preservation of immune function, appears to be most likely to benefit from interferon alpha treatment. A series of clinical trials with highly purified interferon alpha preparations have shown high doses (greater than or equal to 20 X 10(6) U/m2) to be superior to low-dose treatment. Thus far, there is no convincing evidence to suggest that the combination of interferon alpha with cytotoxic chemotherapy improves its antitumor activity. Preliminary trials of interferon gamma have failed to demonstrate significant activity against KS, but the potential of interferon gamma to prevent or treat some of the infectious complications of AIDS has yet to be adequately addressed. In vitro studies showing that interferon alpha (alone and in combination with other antiretroviral agents) can inhibit replication of the human immunodeficiency virus, suggest further studies to evaluate its activity against the etiologic agent responsible for AIDS.